Stable, Highly Efficient, Commercially Relevant Organic Solar Cells Through Interface and Interlayer Optimization
Abstract
Mission needs and research opportunity. With single layer Organic Solar Cells (OSCs) now approaching >20%, the deployment of OSCs as flexible electric power sources with high power/weight ratios can now be envisioned ever more clearly. Performance parameters other than power conversion efficiency of as-cast devices on glass substrates are now demanding attention and solutions. Specifically, understanding and controlling the stability and robustness of flexible OSCs has become a paramount concern for eventual deployment ofOSCs in the battlefield and society at large. Knowledge/capability gap. Currently used charge-selective transport interlayers exhibit or introduce instability and performance problems that need to be eliminated.Overall Objective. We will achieve comprehensive fundamental understanding on how OSC stability and performance can be enhanced with the use of small molecule or polymer interface modifiers (aka buffer layers) between the active layer and cathode and anode charge transport interlayers. Our objective is to develop and deploy a multi-pronged and comprehensive approach to delineate the fundamental science of buffer layers function to increase performance and stability. The programmatic goal is to achieve operating lifetimes >10 years with ~17% research efficiency from synthetically simple materials. Overall approach: This proposal builds on the knowledge foundation of morphological stability and mechanicalrobustness developed by the Ade and O#Connor groups during the prior ONR OSC funding period. Active layer materials systems targeted for in-depth, deep understanding are based on commercially available semi-conducting donors and non-fullerene molecular acceptors (NFAs), but with a selection that is informed by what has been learned about mechanical and morphological stability from the prior work and what is known about intrinsic photostability, cost and processing window. A number of complementary processing and characterization methods willbe used to investigate and isolate the contribution of buffer layers from other factors on performance and stability. Although the proposed research is fundamental in nature, we will include commercially interesting materials on account of their cost or processing window. The research will be informed by partnerships with world-leading OSC indoor module producer Epishine from Sweden and PolyPV, a young, small US company with two employees and ONR phase-II STTR support. This partnership approach is necessary as OSC development is a complex optimization process where costs, fabrication ease, performance, and stability are all inter-related and often in tension. We will develop engineered interfaces and buffer layers that minimize impact on other important OSC parameters.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 08, 2024
- Source ID
- N000142412104
Entities
People
- Harald Ade
Organizations
- North Carolina State University
- Office of Naval Research
- United States Navy